Explicitly enable encryption (thanks marneu!) & remove unnecessary postinst.
When I was putting together the packaging, I used @agaida's brilliant idea to explicitly express the configuration options in debian/rules. Unfortunately, I neglected to notice the fact that his packaging had turned off encryption support, so I turned it back on.
I also got rid of the kind of pointless postinst that was in there, as vorlon had pointed out.
Test Plan: Do some encryption :)
Reviewed By: tsimonq2
Differential Revision: https://phab.lubuntu.me/D34